JP3268859B2 - Screen alignment method and apparatus for screen printing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen printing machine for applying a coating agent on a printed circuit board mounted on a table via a printing screen.

[0002]

2. Description of the Related Art As a prior art, a printing material fixing base on which a printing material is fixed is horizontally moved and lifted relative to a plate fixing portion on which a printing plate is fixed, so that the printing material is positioned at a printable position. A test print is performed, the printed matter is positioned below the video camera, a printed image of the printed matter observed by the video camera is projected on a monitor television, and a reference point of the printed matter projected on the monitor television is set at a reference point of the monitor television. Then, the master printed material accurately printed is replaced with the test print material and fixed to the print material fixing table, and the operator adjusts the reference point of the image to the reference point of the monitor television. Japanese Patent Application Laid-Open No. Sho 61-123543 discloses a technique in which a substrate to be printed is moved using knobs for adjusting the X, Y and θ directions, respectively.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to simplify a plate matching operation in the prior art.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a screen printing machine for applying a coating agent to a printed circuit board mounted on a table through a printing screen. The pattern is recognized by the recognition camera, the respective positions are stored in the first storage device, and the position correction is performed based on the positional deviation between the position of the recognized positioning mark and the position of the set positioning mark. After that, the substrate is printed, the printed pattern of the printed substrate is recognized by a recognition camera, and the amount of positional deviation is calculated based on both the recognition result of the printed pattern and the recognition result of the circuit pattern. The next time the substrate is printed, the position of the alignment mark on the substrate is recognized by the recognition device, and the positional deviation amount from the position of the alignment mark that has been set is calculated. It is intended to fit relatively position the substrate and the printing screen on the basis of the positional deviation amount between the printing pattern and the positional deviation amount and the circuit pattern of the test print substrate.

Further, the present invention recognizes the position of an alignment mark on a printed circuit board placed on a table, compares the recognized position with the position of the set alignment mark, and corrects the position by the amount of deviation. In a screen printing machine that applies a coating agent to a printed substrate through a printing screen, the recognition and pre-
A recognition camera for recognizing a print pattern printed after correction for the amount of misalignment, a comparison device for comparing both the recognition results of the circuit pattern and the print pattern recognized by the recognition camera, A calculating device for calculating a shift amount between the two patterns based on the result, a storage device for storing the shift amount calculated by the calculating device, and a position of the board recognized by the recognition camera at the next printing of the board. The substrate and the printing screen are moved based on the amount of misalignment between the position of the alignment mark and the position of the set alignment mark and the amount of misalignment between the two patterns of the test printing substrate stored in the storage device. And a control device for performing relative positioning.

[0006]

According to the above arrangement, the recognition mark and the circuit pattern are recognized by the recognition camera,
Further, the position of the recognized alignment mark is compared with the position of the set alignment mark, and the print pattern of the test printing substrate on which printing has been completed after the deviation amount has been corrected is also recognized. Then, the positional deviation between the circuit pattern and the print pattern is compared by a comparing device, and the amount of the deviation is calculated by a calculating device and stored in a storage device.

Next, at the time of screen printing of the present board, the amount of misalignment between the position of the registration mark of the board recognized by the recognition camera by the control device and the position of the set registration mark and the storage The printing screen and the substrate are relatively positioned based on the amount of positional deviation between the circuit pattern of the test printing substrate and the printing pattern stored in the apparatus.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to FIGS.

(1) is a suction table on which a printed board (2) provided with alignment marks (2A) and (2B), which is transferred by a board transfer device (not shown), is mounted by suction. ) Are a pair of front and rear guide rails (3) which are a linear motion mechanism in the X direction.
(4) An X-direction output shaft movably arranged on the upper side and having a feed screw formed by an X-direction feed servomotor (5) arranged in parallel with the one guide rail (3). The suction table (1) is moved from the positioning station (A) to the printing station (B) by forward and reverse rotation of the output shaft (6) via a connecting member (7). ) Is controlled to move in the X direction.

The suction table (1) has a pair of left and right Y-direction output shafts (8) and (9) extending along the Y direction, as shown in FIG. 1st and 2nd spindle members (10) (11), these 1st and 2nd
Sliding parts (10A) (11) of the shaft members (10) (11)
The first and second fitting members (14) supported by being rotatably fitted in the horizontal direction (θ direction) via the shafts (12) and (13) fixed to A). (15), and are slidably disposed on the guide rails (16) and (17) and the Y-direction output shafts (8) and (9) along the first and second Y directions. And the other of the first and second fitting members (14) and (15)
It is fixed to both left and right sides of the suction table (1).

The first fitting member (14) has a shaft (1).
2) is adapted to be completely fitted, and the second fitting member (15) is notched at its outer portion so that there is play in the fitted state with the shaft (13). For this reason, the shaft member (10) (1
Even if the movement distance of 1) is different and the distance between the shafts (12) and (13) is changed, the fitting state of the shaft (11) and the second fitting member (15) is within the range of the above-mentioned play. And the suction table (1) rotates smoothly by θ.

That is, the first spindle member (10) is rotated by the first correction servomotor (18) to rotate the first Y-direction output shaft (8) forward or backward. While the right side of the suction table (1) is moved in the YA direction, the rotation of the suction table (1) can be controlled in the θ direction about the shaft (12), while the second support member (11) Y
The direction output shaft (9) is connected to a second correction servomotor (19).
By rotating the suction table (1) in the forward and reverse directions by moving the left side of the suction table (1) in the YB direction, the rotation of the suction table (1) can be controlled in the θ direction about the axis (12). As shown by the dotted line in the drawing, the suction table (1) is rotated in the θ direction about the axis (12) due to the difference between the displacement in the YA direction and the displacement in the YB direction. The position of the substrate (2) is regulated together with the linear motion mechanism in the θ direction also as the motion mechanism.

(20) is a recognition camera, and a connecting member (2)
A moving mechanism (23) that moves in the Y direction by driving a camera feed servo motor (22) via 1) is disposed at a position directly above the guide rails (3) and (4). An output shaft (not shown) that rotates forward and reverse by the drive of the servomotor (22) is provided, and the connecting member (21) is connected and screwed to the output shaft, so that the recognition camera (2) is provided.
0) is moved in a direction (Y direction) orthogonal to the transport direction (X direction) of the substrate (2).

A printing screen (24) is disposed above the printing station (B) on the right side of the guide rails (3) and (4).
4) is composed of a screen plate (25) and a screen frame (26) surrounding the screen plate (25).

(27) a keyboard (28) as an input device for setting various data, a teaching key (30) as a screen selection key of a monitor television (29), a start key (31) for starting a screen printing machine, The operation unit includes a manual key (32) for manually performing a printing operation, an automatic key (33) for automatically performing a printing operation, and the like.

Reference numeral (34) denotes a RAM as a storage device for storing various setting data such as alignment marks (2A) and (2B) on the substrate (2), circuit patterns, and reference positions of printed patterns.

A ROM (35) stores a given program related to a printing operation.

(36) A CPU as a control device, which performs given control according to the various setting data.

(37) is an interface.

Reference numeral (38) denotes a suction table drive source for driving the suction table (1). The X-direction feed servo motor (5), the first correction servo motor (18), and the second correction servo are provided. It consists of all motors (19).

Hereinafter, the operation will be described in detail with reference to the drawings.

Here, the setting operation of the adjustment data as the device offset will be described.

First, the data setting board (2) transferred from the upstream apparatus is located at the printing station (B).

Then, the operator looks at the circuit pattern of the substrate (2) from above through a screen opening (not shown) of the printing screen (24), and if the opening matches the circuit pattern, registration is performed. No action is required,
The adjustment offset is zero. If there is a displacement, the table (1) is moved in the X, Y, and θ directions via the suction table drive source (38) to perform a registration operation.
This correction amount is used as an adjustment offset in the RAM.
(34). Hereinafter, the description will be continued assuming that the adjustment offset data (X0, Y0, θ0) exists. Note that this eye-matching operation may be performed using a recognition camera.

Hereinafter, the printing misregistration operation will be described.

First, at a positioning station (A), a test printing substrate (2) carried by a substrate carrying device is placed on a suction table (1) and positioned and suctioned by a positioning mechanism (not shown). Then, the suction table (1) is moved in the X direction by driving the X-direction feeding servo motor (5) having a feeding function and a correction function to the substrate (2), and reaches the recognition station. (20), the mark (2A) is recognized. At this time, the moving position of the suction table (1) is determined by the positioning mark (2) on the substrate (2) whose position data is stored in the RAM (34).
A) is set so as to be sent to a position immediately below the recognition camera (20), and if there is no misalignment in the alignment mark (2A), the alignment mark (2A) is displayed on the cross line of the camera (20). Is located.

Next, the alignment mark (2) stored in the RAM (34) by the moving mechanism (23) for driving the recognition camera (20) by the camera feed servo motor (22).
B) is moved to a coordinate position expected to be located, and the position is recognized.

Then, the alignment mark (2A)
Based on the recognition data of (2B), the amount of mark position deviation from the data stored in the RAM (34) is recognized, and the amount of deviation is compared by a comparison device (not shown) in the CPU (36). Not calculated by the calculator. The shift amount has a correction component in the X, Y, and θ directions. Then, the deviation amount is calculated by the calculation device in the X direction, the YA direction, and the Y direction.
It is decomposed into a correction component in the B direction. At this time, in the Y direction and the θ direction among these correction amounts, if it is desired to perform correction by y in the Y direction and θ1 in the θ direction, the correction amount in the YA direction is the correction amount in the y and YB directions. Is y + Ltanθ1
(L: distance between shaft supports).

Then, the X direction, Y
The correction amounts in the direction and the θ direction are stored in the RAM (34).

Hereinafter, the teaching operation for aligning the circuit pattern on the substrate (2) will be described.

The recognition camera (20) is positioned above the first coordinate position (X1, Y1) of the circuit pattern stored in the RAM (34). At this time, the operator does not need to perform the alignment teaching operation if the desired alignment position is located on the cross line of the camera (20), and performs the alignment teaching operation if there is a misalignment. That is, the table (1) and the camera (20) are moved so that the desired alignment position is located on the cross line while looking into the camera (20), and the position after alignment is (X3, Y3). Recognizing that there is a RAM (3
Store in 4).

Next, the recognition camera (20) is positioned at the second coordinate position (X2, Y2) of the circuit pattern, and if there is a positional deviation, the operator performs the alignment teaching operation as described above, and The combined position (X4, Y4) is recognized and stored in the RAM (34).

Then, the suction table (1) is conveyed to the printing station (B) by driving the servo motor (5) for feeding in the X direction. At this time, the alignment mark (2
A) The X-direction feed servo motor (5) is instructed by the CPU (36) based on the correction amounts in the X-direction, Y-direction and θ-direction obtained from the recognition data of (2B) and the value taking into account the adjustment data. , The first correction servomotor (1
8) and the second correction servomotor (19) are drive-controlled to move and adjust the suction table (1), whereby the alignment marks (2A) (2B) on the substrate (2)
Is corrected so as to come to a regular position. That is, the X-direction correction of the suction table (1) is performed by driving the X-direction feed servomotor (5), and the Y-direction and θ-direction corrections are performed by the two servomotors (18) and (19). The support members (10) and (11) are Y
Directional output shafts (8) (9) and guide rails (16) (1)
7), and the suction table (1) is corrected and moved to a regular position via the fitting members (14) and (15).

Here, the suction table (1) is lifted by an elevating mechanism (not shown) to bring the substrate (2) close to the printing screen plate (25). Is screen printed.

Hereinafter, a description will be given of a teaching operation of registering a printed pattern on the printed board (2).

The printed substrate (2) is returned to the recognition station and the above-mentioned RAM (34) for the printed pattern is obtained.
Of the first point of the circuit pattern (X
(1, Y1) The recognition camera (20) is located above. Then, as described above, if the desired registration position of the print pattern is located on the cross line of the camera (20), there is no need to perform registration teaching.
If there is a positional deviation, a matching teaching operation is performed. That is, as described above, the table (1) and the camera (20) are moved so that the desired matching position is positioned on the cross line while looking into the camera (20), and the matching positions (X5, Y5) RAM (3
Store in 4).

Next, the recognition camera (20) is positioned at the second coordinate position (X2, Y2) of the circuit pattern, and if there is a displacement, the operator performs the matching teaching operation as described above, and The matched position (X6, Y6) is recognized and stored in the RAM (34). From these data, the amount of printing displacement caused by the displacement of the printing screen (24) due to the printing pressure of the squeegee due to the movement of the squeegee during printing is recognized.

Then, the operator releases the suction of the suction table (1), removes the substrate (2), presses the automatic key (33), presses the start key (31), and performs subsequent printing. Perform the operation automatically. In other words, a new substrate for final printing (2) is transferred onto the suction table (1) by the substrate transfer device, and is positioned and mounted. In this state, the alignment marks (2A) and (2B) are recognized by the recognition camera (20) as described above, and the recognition data and the RAM are recognized.
The position is compared with the regular position stored in (34).
The shift amount is calculated. And the printing station (B)
At the time of moving to the position (X3, Y3), (X4, Y) of the print pattern obtained from the adjustment data and the test printing substrate (2).
4) and print pattern positions (X5, Y5), (X6, Y
6) Adsorption table (1)
Is corrected, the printing operation is performed in the printing station (B), and the printed substrate (2) is discharged.

Further, in this embodiment, the center of the circuit pattern and the printed pattern is aligned on the cross line of the camera (20). The center may be obtained by a calculation device by aligning each corner with the cross line.

[0040]

As described above, according to the present invention, the relative positioning operation between the printing screen and the printed circuit board is simplified .
Of course, the registration mark
Between the mark position and the set alignment mark position.
Print the board after correcting the alignment based on the misalignment
And recognizes the printed pattern of the printed board with a camera.
Recognition, based on the recognition result of both the printed pattern and the circuit pattern
Calculate the amount of displacement and store it in the storage device.
When printing, set the position of the alignment mark on this board.
Calculate the amount of misalignment with the position of the alignment mark
The amount of misalignment and the circuit pattern of the test print substrate
Board and print screen based on the amount of misalignment between
Position is relatively aligned with the
Position of the alignment mark on the
Alignment correction based on the misalignment with the alignment mark
After performing the correction, the board is printed, and the printed pattern of the printed board is printed.
Turns are recognized by a recognition camera, and printed patterns and circuit patterns are
The amount of misalignment is calculated based on the recognition results of
Between the printed pattern printed on the printed circuit board and the circuit pattern.
The position shift amount can be calculated more accurately.
As a result, the relative position of the printed screen
The accuracy of the target alignment operation can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration circuit diagram of a screen printing machine.

FIG. 2 is a plan view of the screen printing machine.

FIG. 3 is a plan view schematically showing an operation state of a positioning station in the screen printing machine.

FIG. 4 is a diagram showing an operation flowchart of the screen printing machine.

FIG. 5 is a diagram showing an operation flowchart of the screen printing machine.

FIG. 6 is a diagram showing an operation flowchart of the screen printing machine.

[Explanation of symbols]

 (1) Suction table (2) Printed circuit board (2A) Alignment mark (2B) Alignment mark (5) Servo motor for X-direction feed (18) First servo motor for correction (19) Second servo for correction Motor (20) Recognition camera (22) Camera feed servo motor (24) Print screen (34) RAM (36) CPU

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B41F 15/00-15/46 H05K 3/12

Claims (2)

(57) [Claims] In a screen printing machine for applying a coating agent to a printed board mounted on a table via a printing screen, an alignment mark and a circuit pattern of a board for test printing are recognized by a recognition camera. Is stored in the first storage device, and the substrate is printed after performing a position correction based on a position shift between the position of the recognized positioning mark and the position of the set positioning mark, The printed pattern of the printed board is recognized by a recognition camera, the amount of positional deviation is calculated based on the recognition result of both the printed pattern and the circuit pattern, and stored in the second storage device. Sometimes, the position of the alignment mark on the substrate is recognized by the recognition device and the amount of positional deviation from the position of the alignment mark that has been set is calculated, and the amount of positional deviation and the position of the test print are calculated. A screen positioning method for a screen printing machine, comprising: relatively positioning a substrate and a printing screen based on a positional deviation amount between a circuit pattern of the substrate and a printing pattern. 2. The method according to claim 1, further comprising: recognizing the position of the alignment mark on the printed circuit board mounted on the table, comparing the recognized position with the set position of the set alignment mark, and correcting the position by a shift amount. In a screen printing machine that applies a coating agent through a printing screen, the position of the test printing substrate
Recognition of alignment mark and circuit pattern
A recognition camera for recognizing a printed pattern printed after the correction has been performed, a comparison device for comparing both recognition results of the circuit pattern and the print pattern recognized by the recognition camera, and a comparison device for comparing both recognition results based on the comparison result. A calculating device for calculating the shift amount between the patterns, a storage device for storing the shift amount calculated by the calculating device, and the position of the alignment mark of the board recognized by the recognition camera at the next printing of the board. The substrate and the print screen are relatively aligned based on the amount of positional deviation from the set position of the alignment mark and the amount of positional deviation between the two patterns of the test printing substrate stored in the storage device. A screen alignment device for a screen printing machine, comprising: